When we want to use an electronic instrument, such as a scanning apparatus, the plug of the scanning apparatus is inserted in a wall outlet which, in turn, is connected electrically to an electrical power source in the house. Sometimes, the wall outlet may be shielded by a large furniture or is already occupied by the plug of another electronic instrument already present in the house, a plug adaptor assembly is required in order to connect all the electronic instruments electrically to the power source. In addition, there are limited number of wall outlets in a room, but there may be several domestic electronic instruments in the same room, such as a TV set, an air conditioner, a washing machine, an electric oven and so forth, all of which require electrical power for operating the same.
Referring to FIG. 1, a conventional plug adaptor assembly 10 is shown to include a plug member 104 inserted into the wall outlet (not visible) so as to be in electrical communication with a power source, and an adaptor member 102 formed with two plug holes 106, 108 of different standard dimensions. When desired, the plugs of two different electronic instruments can be inserted respectively into the plug holes 106, 108 of the adaptor member 102. One drawback of the aforesaid conventional plug adaptor assembly 10 resides in that the electronic instruments being used must be disposed adjacent to the wall outlet, thereby unnecessarily restricting the utility range of the electronic instruments.
Referring to FIG. 2, another conventional plug adaptor assembly 20 is shown to include a plug member 104, a connecting cable 202, and an adaptor member 102. The plug member 104 is formed with a plurality of terminals, and is adapted to be inserted into the wall outlet 126 in the wall 122 so as to establish electrical communication between the terminals 128 of the wall outlet 126 and the terminals of the plug member 104. The adaptor member 102 has a rear end formed with two plug holes 106, 108 of different standard dimensions. The connecting cable 202 has two opposite ends respectively connected to the plug member and the adaptor body 102. Though the electronic instrument being used can be disposed rather away from the wall outlet 126 by employment of this conventional plug adaptor assembly, the connecting cable 202 is exposed to the ambient surrounding, which consequently affects the aesthetic effect the entire environment.
Buying different types of conventional plug adaptor assemblies can result in an extra expense and storing the same when not in use is inconvenient to the user.